Dense coatings evenly coated in the rust on the metal surface, so that it is isolated from a variety of corrosive media, is one of the most basic method of pipeline corrosion protection. Since the 70 's, piping in the harsh environments such as polar, Ocean, oil heating, such as transporting the pipe temperature, more demands on coating performance. Therefore, the pipeline anticorrosion coating are increasingly using composite or composite structure.
1, the outer wall coating: pipe outer wall coating material types and conditions of use.
② within the anti-corrosion coating: in order to prevent pipe corrosion, reduces friction, increasing throughput and applied to a film on the inner wall of the pipe. Coating commonly used with amine curing epoxy and polyamide epoxy coating thickness 0.038~0.2 mm. In order to ensure the coating and bonding the tube wall, must deal with on the inner wall surface. Since the 70 's trend to the inside and outside wall coating used the same materials, so that the coating of the inner and outer walls simultaneously.
③ anticorrosion and thermal insulation coating: heat transmission medium and small diameter of pipeline of crude oil or fuel oil, to the soil to reduce the pipe heat pipe external layer with insulation and anti-corrosion of composite. Common insulation is rigid polyurethane foam, application temperature of-185~95℃. This material is loose, to increase its strength, outside of the insulation layer and apply a layer of high density polyethylene layer, formed composite structures to prevent infiltration of groundwater into insulation.